Process of and apparatus for forming explosive powder into spherical grains.



E. DU FONT.

PROCESS OF AND APPARATUS FOR FORMING EXPLOSIVE POWDER lNTO SPHERICAL GRAINS.

APPLICATION FILED JUL-Y 3|. 1915.

1,162,757, Patented Dec. 7, 1915.

llYVE/V 7017 JIMENEZ ITED sran ii ERNEST m1 FONT, or wILMmGroN, DELAWARE, AssIGNoie BY DIRECT AND MESNE ASSIGNMENTS, rqBALL cream EXPLOSIVES ooMrANg'or WILMINGTON, DELA- WARE, AaCORPORATION F DELAW'ABE.

PROCESS OF APPARATUS FOR FORMING EXPLOSIVE POWDER INTO SPHERICAL GRAINS.

Application filed July 31, 1915.

for Forming Explosive Powder-into Spherical Grains, of which the following is a full,

clear, and exact description, reference being had. to the accompanying drawings, which form av part of this specification.

The object of my invention is to improve the known method of manufacturing granular black powder into approximatelyspherical grains'so as to substantially increase the product. i

In a process patented by Francis I. du Font and myself August 4, 1914, No. 1,106,087, the explosive is prepared in'the form of a somewhat pasty mass, which is then divided into separate particles, which are rolled upon a heated surface until they are dry An emcient apparatus for practisingsaid process is described in sald patent, said apparatus having been patented by said Francis 1. du

Pont on the same date, No. 1,106,138.

In this apparatus, the specific/means disclosed for rolling and drying the particles is an inclined rotary cylinder with heated walls. Said process and apparatus is practicable, eflicient and successful, but care must be taken not to deliver the powder too rapidly into the rounding and drying cylinder, as otherwise the grains are apt to become soft and coalesce into masses. words, the practicable capacity of the grainforming mechanism substantially exceeds the capacity of the rounding and drying mechanism. Y The object of my invention is to substantially increase, the capacity of the rounding and drying mechanism, in order that the output of the apparatus as a whole may be substantially. increased and with a view, also, of overcoming all tendency of the grains to soften and mass. I

The invention will be bestunderstood by first referring to and explaining the accompanying drawings, which show a. preferred form of improved apparatus forcarrying out the improved'process.

Figure 1 is a side view partly in section,

Specification of Letters Patent.

In other PatentedDec. 7, 1915.

Serial 110 42383.

of a part-of the apparatus. Fig. 2'is a side view, partly in section, showing, partly diagrammatically, the remaining portion of the apparatus (shown partly in end view in Fig. 1).

The explosive ingredients, in the form of a pasty mass, as explained in the above mentioned patents, are introduced into a rotary whereby the material is forced down toward' the open bottom of the hopper. On the lower end of the shaft are inclined blades h, which press the material into holes i in a fiat horizontally-extending revoluble annular rim j of a wheel 7' in a. vertical axis. The holes 2' extend entirely around the wheel near its periphery. A stationary plate or guard 0 underlies the part of the wheel which at any given moment is beneath the hopper mouth and prevents the powder being forced out of the holes. A wheel 1? turns on a horizontal axis within a vertical plane extending radially of the axis of the wheel j and has 011 its periphery a number of ejectors g which engage the holes in a manner somewhat similar to that in which a sprocket wheel engages a sprocket chain and force the pl fs' of powder within the holes to the lower dgc thereof, a knockoff, preferably in the form of a moving thread t, effecting the complete detachment of the plugs. The foregoing apparatus is the same as that more fully described in said patents.

In the apparatus of said patents, the detached plugs fall into a hopper, whence they pass into an inclined rotary rounding and drying cylinder having steam jacketed walls,

. similar to the vessel 10 shown in Fig. 2. In

my improvement, however, another stepthat of preliminarily slightly drying the surface of the grainsis interposed in the process, which step I prefer to carry out by "means of the mechanism, shown in Fig. 2,

. veyer forming a drying chamber into which hot air may be delivered from a pipe 2. The projections y are shown as supported from the hood 2'. As the powder travels along the belt, the grains are turned over by the projections, thus exposing all sides of the grains to. a drying action. In the cylinder w the plugs are rounded and the drying operation is completed. The length of time the powder should undergo this treatmentwill vary according to the'aniount of powder which is delivered to the belt. [he

following example may be given: With a delivery of 200 pounds an hour, an exposure to a drying atmosphere, preferably a heated atmosphere, of-about six or seven minutes has. the effect of obviating the possibility of coalescence of the grains, thus permitting the cylinder to to effectively. handle a much larger quantity of powder than would otherwise be the case.

Having now fully described my invention, What I claim and desire to protect by Letters Patent/is:

l. The process of forming explosive powder into grains whose shape tends to he spherical, which consists in dividing a pasty mass of the'explosive into separate particles,

' then ex )osin the articles to a, )reliminar D surface-drying operation, and then simultaneously. heating and agitating the same.

2. The process of forming explosive powder into grains whose shape tends to he spherical, which consists in diyiding a pasty mass of the explosive into separate particles, then exposing the particles to a preliminary drying action, and then rolling the particles upon a heated surface.

3. The process ofiorining explosive powder into grains whose shape tends to he spherical, which consists in dividing a pasty mass of theexplosive into separate particles of non-spherical shape, then drying the surfaces of the particles, and then rolling the particles upon aheated. surface.

4. The process of forming explosive pow/ tier into grains whose shape tends to he spherical, which consists in dividing a pasty mass of the explosive into separate particles of cylindrical shape, then drying surfaceso't the particles, and then rolling the particles upon. a heated surface.

5.- The process of forming explosive pow der into grains whose shape tends to he spherical, which consists in dividing a pasty =.--masso f the explosive into separate particles,

:then subjecting .the particles to a prelimwinaryfdrying operation and turning over heated suriacc to form the particles to expose all sides thereof to the drying action, and then rolling the par ticles upon a heated surface.

(5. The process of forming explosive powder into grains whose shape tends to be spherical, which consists imdividing a pasty mass of the explosive into separate particles, then subjecting the particles to the action of heated air to preliminarily surface-dry them, and then rolling the particles upon a heated surface.

7. The process of forming explosive powder into grains whose shape tends to be spherical, which consists in dividing a pasty mass of the explosive into separate particles of cylindrical shape, then subjecting the particles to the action of heated air andeturnin over the particles to expose all sides thereof to the drying action, and then rolling the particles upon a heated surface and continuing to roll them thereon until they are dry.

8. The process of forming explosive powder into grains whose shape tends to be spherical, which consists in dividing a pasty mass oi? the explosive into separate particles of non-spherical shape, then subjecting the particles to a surface drying action While maintaining them in substantially the same shape, and then rolling surface to change them into an approximately spherical form and at the same time thoroughly dry them.

9. In a machine for forming explosive powder into grains whose shape tends to be spherical, the combination with means adapted to separate the explosive into separate particles, of means to surtacedry the particles, and means presenting a moving the particles into balls.

it). in a machine for forming explosive powder into grains whose shape tends to be spherical, the combination. with adapted to separate this explosive into separate particles of non-spherical shape, of,

means preliminarily dry the particles, and means presenting a moving heated surface to complete the drying (U. the particles and torn; them into balls.

l1. ls. a machine for forming explosive per-idler into grains whose shape tends to he spherical, the combination with means adapted to separate the explosive into sep arate particles of cylindrical shape, of means to superficially dry the particles, and means presenting a. moving heated surface to round oil', and complete the drying of said particles. 12. in machine for forming explosive powder into grains ivhose shape tends be spherical, the combination with means adapted to separate the explosive into separate particles, of a (.lrying chamber, coni'eyer to carry said. particles through them upon a heated means drying chamber, and means presenting a moving heated surface toreceive the par- 'ticles and shape them into approximately spherical form. V

13. In a machine for forming explosive powder into grains whose shape tends to be spherical, the combination with means adapted to separate the explosive into separate particles, of an apparatus for drying and rounding the particles, and means interposed between said means and apparatus to V preliminarily dry the particles and turn them over to expose all sides thereofto the surfacealrying action.

14. In a machine for forming explosive powder into grains whose shape tends to be spherical, the combination with means adapted to separate the explosive into separate particles, of a drying chamber, a conveyer to carry said particles through the drying chamber, projections adapted to an rest the travel of the particles and turn them over, and an apparatus for finally drying and rounding the particles.

15. In a machine for forming explosive powder into grains whose shape tends to be spherical, the combination with means adapted to separate the explosive into separate particles, of an apparatus for drying through which heatedair is admitted to said chamber, projections in said chamber to arrest the travel of the particles and turn them over, a revoluble inclined cylinder Whose.

upper end communicates with the discharge end of the conveyer, and means to heat the inner wall of the cylinder.

In testimony of which invention, 1 have hereunto set my hand, at Philadelphia, on this 30th day of July, 1915.

ERNEST Dio PONT. 

